NEW YORK (TheStreet) -- One of the big stories this week was the Christie's Auction which saw a 44-year old painting, "Lucien Freud" by Francis Bacon, sell for $142 million, and a sculpture meant to look like a children's birthday party animal, Balloon Dog by Jeff Koons, sell for $58 million.

Also drawing attention were diamond sales. A 14-carat orange diamond sold at Christies for $36 million. And in Geneva, Switzerland a 59-carat pink star diamond sold for $83 million dollars.

One of the many criticisms of the U.S. Federal Reserve Bank's zero-interest rate and quantitative easing policies is that it disproportionally benefits the wealthiest among us by squeezing asset prices higher -- further widening the wealth gap as the so called 1% obviously own most of the assets.

As one of many measures of the growing wealth gap, CEO pay between 1978 and 2011 increased by 725% while worker pay increased by 5.7%, according to the Economic Policy Institute. A wide wealth gap is generally accepted as being a contributing factor to the Great Depression.

Today, the wealth gap is wider than it was back then with the top 1% of the population estimated to own 40% of the country's wealth, according to

Another sign of excess could be the rumored $3 billion that Facebook ( FB - Get Report) offered to Snapchat, a company with reportedly no revenue.

There have been funds over the years that have come and gone, including the old Claymore Robb Report Global Luxury Index ETF, and there have also been funds that invest in art that have tried to capture this theme. For now the easiest way to try to capture these signs of excess is the PureFunds ISE Diamond/Gemstone ETF ( GEMS).

GEMS owns companies involved with the gemstone business including retailer Signet Jewelers ( SIG - Get Report) and Petra Diamonds Limited ( PDMDF)which has mining operations in Africa, but whose stock is traded primarily in London.

As a global fund, the U.S. is the largest country at 28%, followed by Hong Kong at 25% and Canada at 20%. At the industry level, GEMS is mostly jewelry stores, but does allocate more than 40% to companies that either mine diamonds or explore for diamonds.

When the fund launched in November 2012 I wrote about it -- noting it may not be an investor's best friend because of its narrowness, and that whenever the next recession comes along the fund is likely to be hard hit because of how sensitive jewelry purchases are to the economic cycle. For example, Signet Jewelers fell 80% during the last bear market.

Another aspect of diamond purchases is the flight-to-safety aspect where people can effectively hide or park assets in diamonds because they are very small, yet very expensive. A fund investing in diamond companies should not be expected to offer that attribute because ultimately the fund owns stocks not actual diamonds.

A Chicago-based firm called GemShares has filed for a physically backed diamond ETF along the lines of physically backed precious metals funds like the SPDR Gold Trust ( GLD - Get Report), but there is no word yet on when or if the fund will actually list. Whereas the gold that backs GLD is stored in a vault that is about the size of a large hot tub, it's amusing to think that if a physical diamond ETF were to ever start trading, its entire asset base could fit in an envelope.

Realistically, there is no effective way to capture the excesses exhibited in the art or precious stones market through exchange-traded products. If you are in the so-called 1% then you may be able to simply buy the real thing but the rest will need to wait for a more effective product to come to the market.

At the time of publication, the author had GLD as a personal holding.

This article is commentary by an independent contributor, separate from TheStreet's regular news coverage.